This invention relates to a press-connecting terminal having a press-connecting blade into which an electric wire covered with an insulation material, such as a synthetic resin, is press-fitted to make an electrical connection, and also to a connector having such a press-connecting terminal.
There are known various kinds of connectors for use with a wire harness and in other fields. Also, there are various kinds of connection terminals used with such connectors. Usually, such a connection terminal is formed from an electrically-conductive metal sheet by stamping and shaping. For easily connecting such a terminal to a covered wire without removing a cover of the wire, a press-connecting terminal has been extensively used.
As shown in FIG. 7, a press-connecting terminal 70 includes a wire connection portion 70a, and an electrical connection portion 70b for connecting to a mating terminal. The wire connection portion 70a has a press-connecting blade 72 defining a slot 71 into which a covered wire 73 is adapted to be press-fitted, an insulation barrel 78 for fixing the covered wire 73 in the slot 71. The press-connecting blade 72 and the insulation barrel 78 extend upwardly from a bottom portion 76 (see Japanese Utility Model Unexamined Publication No. 4-15160).
When the wire 73 is press-fitted into the press-fitting blade 72 defining the upwardly-opening slot 71 generally u-shaped, the press-fitting blade 72 cuts the covering of the wire, and is urged into contact with a conductor of the wire 73, thereby making an electrical connection. Structurally, the press-connecting portion constituted by the U-shaped slot 71 is easily affected by an external force such as a pulling force applied to the wire. Therefore generally, the insulation barrel 78 disposed rearwardly of the press-connecting blade 72 is clamped to the outer periphery of the wire 73 so that the terminal can withstand an external pulling force.
When a wire harness, using this kind of press-connecting terminals, is to be formed, or is to be installed on a vehicle, a large external pulling force is applied to the wire. Therefore, there has been proposed a press-connecting terminal 80 shown in FIG. 8, in which two insulation barrels 78 are provided. A convex portion 79 is provided between the two barrels so as to suitably bend a wire, thereby offering a greater resistance to the pulling.
In the conventional press-connecting terminals, when it is intended to enhance the ability of retaining the wire, it is necessary to provide the two insulation barrels and to increase the height of the convex portion between the barrels, which means that the wire connection portion must be increased in size. However, this convex portion is formed by folding the metal sheet from which the press-connecting terminal is formed, and therefore for increasing the height of projection of the convex portion. The metal sheet for forming the terminal must be correspondingly increased in size. The shaping of the sheet, including the folding operation, becomes cumbersome.
This kind of press-connecting terminal has been required to be simplified in overall construction so as to reduce the amount of the material to be used and also to facilitate the shaping operation. This requirement is contrary to the function of enhancing the ability of retaining the wire, and has not as yet been met.